It is proposed to continue the research of the laboratory in the same areas of investigation and at the same level of operation as in the current grant period. The experiments proposed can be grouped around four headings as follows: (a) studies on hemispheric specialization and integration in human patients with complete and partial sections of the forebrain commissures, hemispherectomy, agenesis of the corpus callosum, and patients with related unilateral cerebral lesions; (b) correlated studies on vision in split-brain monkeys using analytic experimental surgery that allows precisely localized and designed disconnections and cortical lesions; (c) studies on selective nerve growth, neurospecificity, and neural plasticity in lower vertebrates and in young and developing kittens and hamsters; and (d) memory processing of one-trial, long-delay conditioned aversive learning in chicks. Future emphasis in the work with human commissurotomy subjects will be shifted in large part to studies utilizing the stabilized optic occluder developed here by Eran Zaidel (1975) for lateralizing prolonged visual input and also the new electronic eye-tracker version of this occluder, the design and development of which has just been completed in a joint collaborative project with Jet Propulsion Laboratories. The engineering, assembly and pilot studies on the latter are completed and we are now ready to proceed.